Members of the Bradford and Bingley Building Society have been warned to take extra care with the shares they will receive if the conversion to a bank goes ahead.
A Rights and Wrongs reader says it could mean some joint names on mortgages losing out in the future - if the relationship breaks up.
The 28-year-old and her husband took out a mortgage with a building society in a joint name to buy a house near Keighley.
Some time later they received £2,500 worth of shares when it converted into a bank. ""I never thought anything about it and the shares were left where they were," she said.
"But since then I have become divorced.
"My husband and I decided before the divorce went through to sell them and split the proceeds.
"But he then sold them without my knowledge and kept the money.
"I phoned the bank but they said they were not even allowed to speak to me about the shares because they were in my husband's name and I had no ownership rights over them even though it was a joint account.
"I just think people should know what can happen.
"I understood all along that they would go to the account and my presumption was that if the account was in joint names the shares would also be in joint names.
"If they are issued just to the first named, I think the other names on the account should have to sign some sort of authority or permission before the shares can be sold.
"I think first of all the Bradford and Bingley should make it very, very clear on the voting forms exactly what people are agreeing to in terms of who gets the shares and whose name they will be issued under."
A Bradford and Bingley spokesman said: "We just can't talk about the whole distribution issue at the moment because we have literally only just set the wheels in motion.
"Normally it is the first named on an account who has the voting rights and that is made very clear to people."
Roger Yeomans, solicitor with the industry watchdog the Banking Ombudsman, said: "We haven't had many complaints about the sort of situation this lady was in, although we have had complaints about the unfairness of shares just going to the first named.
"In fact there is no impediment to building societies giving shares to the other names on the account - whether it's a mortgage or investment account - if that is what the directors recommended and the members voted to approve.
"But practically it is more usual for them to go to the first named.
"As for some sort of authority or permission which has to be signed by the other names, I think it would be worth considering.
"If there was any dispute, the shares would be frozen until it had been resolved.
"But what happens after the shares are distributed is up to the owner and there is nothing to stop the person adding the other names on the account to the shares certificates."
Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.
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